I do not have experience in this hike but I did a quick google search and it looks hard. Here is a rating on alltrails. If the link doesn't work, just go to their website.
https://www.alltrails.com/trail/saint-kitts-nevis/saint-paul-capisterre/mount-liamuiga
Another site, rated it a 7 out of 10.
In 2014, I hiked the Gros Piton from sea level in St. Lucia. I didn't do enough research. It was steep and I got very weak from the elevation. (I thought I was in fairly good shape because the week prior, I ran a half marathon. Not the same. LOL.) It was the most challenging hikes I have ever done. Thank goodness one of the guides had a Coke and the sugar helped me.
Now, I stick to easier hikes because I am not an experienced hiker and would never do something like that again. I won't attempt a "hard" rating on a hike again.
If it's something you really want to do, I would train for it. I hope this helps you.